Alcohol drinking and cigarette smoking are highly correlated with a greater perponderance of heavy smokers among alcoholics than among the general population suggesting a common mechanism in the conjoint abuse of both alcohol and cigarettes (nicotine). The purpose of this study is to establish a role for the endogenous opioid system in nicotine and alcohol dependence by evaluating the ability of the opioid antagonist naloxone, to precipitate withdrawal symptoms, similar to those seen in opiate withdrawal in male and female alcoholics.